Matt, there are other factors at play as well. Doing 5 reps can generate a different effect depending on how you use it. A 5x5 is different than a 1x5, 3x3 is different than 9 singles, etc. Reps are one tool in the toolbox and depending how you use them you will get different results. Other tools in the toolbox would be things like intensity, sets, rest time, etc. You can't build much with just a hammer lol.
If you seperated mass and strength based solely on reps, then 5x5 would be more strength oriented and 3x8 would be mass oriented. But if you counted the reps, the 5x5 would be more total reps than the 3x8...Quite the paradox
